J. Madrenas, MD, C/Vic 12, pral. 2a, E-08006 Barcelona (Spain) Dear Sir, We were very interested in the report of Dr. Kramer et al. [1] concerning digoxin-like immunoreacting activity (DLI A) in uremic serum. The research for an endogenous inhibitor of the membrane Na-K-ATPase has been supported by false-positive results of radioimmunoassays (RIAs) for digoxin in patients with chronic renal failure not receiving cardiac glycosides [1–3]. An inhibition of the Na-K pump activity has also been described in patients on maintenance hemodialysis [4,5]. This abnormality is acutely reversed by hemodialysis and its correction is related with weight loss occurring/during the dialysis session [4]. We investigated DLIA in a group of patients on regular hemodialysis. The RIA for digoxin used was Immo-phase (Corning Medical and Scientific, Medfield, Mass., USA). The limit of sensitivity was 0.040 ng/ml. The intraassay variability was 2.7% and the interassay variability 3.6%. The patient group included 15 males and 9 females aged 17 – 66 years. Ten patients had an urine output which ranged from 150 to 700 ml/24 h. The re1 We wish to thank the staff of ‘CD. Virgen de Montserrat’ for their cooperation in this work. maining 14 patients were anuric. All patients were on unrestricted protein, fluid, and sodium intake. They never had digoxin. Serum sodium and potassium levels, just before the hemodialysis session, averaged 141 ± 2.5 mmol/l and 5.3 ± 0.9 mmol/l, respectively. We assayed two blood samples of each patient at the start of each hemodialysis and immediately after the hemodialysis session. Weight loss during the course of hemodialysis was registered. Only 5 patients had DLIA in their serum (table I); in 3 of them, this was present before and after dialysis with values ranging from 0.052 to 0.13 ng/ml. In the other 2 patients, DLIA was only detected in posthemodialysis samples (values were 0.041 and 0.074 ng/ml). DLIA was unrelated to urinary output and weight loss during the hemodialysis session. Our results confirm the presence of DLIA in serum of patients on regular hemodialysis also. It is important to point out the highly variable values of DLIA according to different RIAs for digoxin [1,3]. In the report of Graves et al. [3], the kit also used by us showed very few falsepositive results in contrast to the RIA used by Kramer et al. [1]. We cannot yet relate the DLIA

We study the variations of CalcJum, Phosphorous and alkal1ne phosphatases in 15 pattents undergoing chronic hemodialysis, treated with propranolol, and we compare the results obtalned to a control group of similar characterlstlcs, as tar as age and time of hemodialysis treatment is concerned. The changes in the amount of plasma calclum and phosphorous was not important. The plasma alkaline prosphatases showed an important tal! in the so treated group, the values af the latter bering inferior to the control group in a similar perlad of time. We can conclude, then, that such a difference would make as think of a halt in the osteogenic activity, secondary to the administratlon of the beta-blockers,

A review is made of the deaths which occurred in a hemodialysis unit between 1969 and 1977. Sixty-two patients were treated during this period, 18 of whom died. The actuarial percentages of survival are also established. The mortality rate was 15.5 percent during the initial period and 31.5 percent after the fourth year. Deaths in the first monts were caused by cardiac and infectious complications. Those occurring at a later period resulted from the lack of good vascular access which is necessary to maintain a good quality of dialysis.